Apparatus for controlling processes of combustion



Aug. 1a; 1925. 1,550,410.

E. P. G. WUNSCH APPARATUS FOR CONTROLLING PROCESSES 0F COMBUSTION Filed Jan. 21. 1925 Mm we 1M $1 a l' tawwv Combustion, of which the Patented 'Aug. 18, 1925.

UNITED STATES 1,550,410 PATENT OFFICE.

ERICK PAUL GUIDO W'O'N SCH, OF STEGLITZ, NEAR BERLIN, GERMANY, ASSIGNOR TO ASKANIA-WERKE A.-G. VOBMALS CENTBALWERKSTATT-DESSAU UND CARL BAM- BERG-I'RIEDENAU, 0F FBIEDENAU, NEAR BERLIN, GERMANY, A CORPORATION OF GERMANY.

APPARATUS FOR CONTROLLING PROCESSES OF COMBUSTION.

Application filed January 21, 1925. Serial No. 3,875.

To aZZ whom it may concern:

Be it knownthat I, Emorr PAUL GUIoo lViiNscII, a citizen of the German Republic, residing at 2 Stindestrasse, Steglitz, near Berlin, Germany, have invented certain new and useful Improvements in or Relating to an Apparatus for Controllin Processes of Following is a specification.

This invention relates to apparatus for controlling processes of combustion in accordance with the nature of the waste gases.

The device is suitable for purposesof most varied kind. It can be utilized, for instance, in boiler or other firing installations, in order to ascertain whether the fuel is sufficiently utilized, and in the case of insufiicient utilization, to efiect a corresponding regulation of the combustion processes; but item also be used in internal combustion engines for the purfpose of regulating the supply of fuel or o the combustion air to suit the nature of the exhaust gases, as well as generall in every case of combustionof solid, liqui or gaseous fuels. The invention essentially consists" in bringing the waste gases into contact with a wire or the like of platinum, palladium or other -mater1al which, in the event of certain combustible ingredients being present in the waste gases, efi'ects a contact combustion with them, with the result that the said wire becomes heated, and its change of length is utilized for effecting the necessary regulation of the combustion rocess. Preferably the suppl of air or fuel is increased or reduced accor to the uirements by the said change 0 length wit the assistance of suitable devices.

- A construction according to the invention is diagrammatically illustrated by way of example in the accompanying drawing. In the drawing, a and b are two -tubes, 1n each of which is arranged a platinum wire c or d; The outer ends of the said platinum wires are sealedin the cylinders or secured in them at points where the sitive and the negative poles of a source 0 electric tension respectively are connected. The inner ends are connected through springs e and f to a tube 9 which can be easily turned about a spindle h. The current passes through the two wires as well as the springs e and f and waste gas passes through the cylinder 0 and is drawn off again through the pipe m, for

instance by means of an ejector pump n connected to the pipe m.

Through the tube 9 passes a fluid under pressure, for instance compressed air or water under pressure, and its open orifice-is arranged opposite two pipes 0 and p, the

openings of which are arranged at one end next to each other, whilst at the other end they are connected to the ends of a cylinder q in which is mounted a piston r.

The working of the apparatus is as follows:

The two wires 0 and d are heated by an electric current to a given temperature. If the waste gas or smoke gas passing through the pipe 11 contains combustible substances, more particularly hydrogen or carbon oxides formed from hydrocarbons or the like, a contact combustion will take place on the wire 0 when the said waste gases pass along it. This results in a heating of the wire a so that it is lengthened, and as the springs e and f are of equal power, the tube 9 W111 be turned to the right in the drawing when the thread 0 is lengthened.

Assuming that previouslythe tube g was exactly in the centre between the openings oi thepipes o and p, half of the escaping fluid under pressure would have passed into each of the pipes o and p. The ressure on both sides of the piston r would have been therefore the same. If the tube 9 is turned to the Tight, a greater portion of the compressed fluid passes through the pipe 0. The pressure on the right hand side of the piston 1' becomes-greater, and the piston is moved to the left. This movement of the piston is utilized by means of a system of rods not shown in the drawing, for effecting the regulation of the combustion process, that'is gases still contain combustible substances,

the air supply could be opened wider, or

the fuel supply closed a little more. As soon as the wlre 0 becomes cooled again, the tube will make a movement in the opposite direction. A corresponding return then again takes place. It is preferable to arrange the tube 9 in such a manner opposite to the openings 0 and p that the device is in its central position when there is just a very slight trace of unburnt substances in the waste gases.

The control, instead of being eifected by means of the tube 9 and piston 1', could be of course effected by means of any other device, for instance the wire a could be connected directly to a system of rods leading to a throttle valve or the like, or the wire a could be utilized to produce directly any other movement required for the regulation.

The tube 1) can generally be in communication with the atmospheric air, but the waste gases escaping from the tube a could also be passed from the tube m after the passage through an intermediate cooling device which cancels the increase of temperature caused by the contact combustion, into the tube 6 in order to draw it ofl or allow it to escape only from the latter. In certain cases there will be no need to arrange the wire d, namely when the varying outer temperature of the room in which the device is mounted, may be neglected, or where it is not of great importance to make the appa ratus highly sensitive.

As a rule, a heating of the wires 0 and (1 will be efi'ected in the manner described by an electric current, but any other heating could be used in its place, and in certain cases it will be possible to do without any heating at all, as on contact of platinum with hydrogen and certain other combustible residues in the waste gases, contact combustion takes place already in the cold.

Instead of making the wires entirely of platinum, palladium and the like, it is also suflicient to make the wires of any desired material, preferably strongly expanding in the heat, and to coat one of them with platinum. In such a case there is even the advantage that both wires could be mounted 1n a single casing through which the waste gases would'be passed, as a surface combustion will take place only on the platinumcoated wire, and accordin ly only that wire will be heated by the unurnt particles of the waste gases.

It is of course also possible, when one wire is made entirely of platinum, to make the second wire of a difierent material, provided that the said material has the same coeflicient of heat expansion.

For the rest, the other construction of the apparatus may be any desired. The only essential point is that the change of length of a wire by contact combustion shall regu late the combustion processes. It is true that it is already known to utilize the change of resistance of a wire caused by contact combustion in indicator devices for indicating the combustion process, but the use of the change of length, namely for direct control of the combustion process, is new.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In an apparatus for the control of combustion processes a wire containing at its surface a metal adapted to effect a contact combustion with combustible materials, means for feeding waste gases of the combustion process to be controlled to said wire and means influenced by the changes of length of said wire effected by the contact combustion, said means being adapted to effect the necessary regulation of the c0mbustion process.

2. In an apparatus for the control of combustion processes a wire consisting of a metal adapted to effect a contact combustion with combustible materials, means for feeding waste gases of the combustion process to be controlled to said wire and means influenced by the changes of length of said wire elfected by the contact combustion, said means being adapted to effect the necessary regulation of the combustion process.

3. In an apparatus for the control of combustion processes a tube traversed by the waste gases, a wire within said tube containing at its surfaces a metal adapted to effect a contact combustion with combustible materials, the one end of said wire being fixed, and means connected to the other end of the wire and being adapted to effect the necessary regulation of the combustion process corresponding to changes of length of said wire effected by the contact combustion.

4'. In an apparatus for the control of combustion processes a tube traversed by the waste gases, a wire Within said tube containing at its surfaces a metal adapted to effect a contact combustion with combustible materials, the one end of said wire being fixed, and means connected to the other end of the wire and being adapted to influence a servo-motor effecting the necessary regulation of the combustion process corresponding to changes of len hof said wire efi'ected by the contact com ustion.

5. In an apparatus for the control of combustion processes a wire containing at its surface a metal adapted to effect a. contact combustion with combustible materials, means for feeding waste gases of the combustion process to be controlled to said wire; a second wire consisting of a metal having a similar heat expansion coeflicienfi as the metal of which consists said first mentioned wire; and means connected to the ends of said wires facing each other, said means being adapted .to efl'ect the necessary regulation of the combustion process correspond ing to changes of length of said first mentionedwire effected by the contact combustion.

' 6. In an apparatus for control of combustion processes 'two wires having the same heat expansion coefiicient the one of which being adapted to be heated by combustible materials contacting it, means for feeding waste gases of the combustion process to be controlled to said wire and means yieldingly connected with the adjacent ends of said wires and adapted to effect the necessary regulation of the combustion process correspondin to changes of length of said wire efi'ected by the contact combustion.

7. In an apparatus-for the control of combustion processes a wire containing at its surface a metal adapted to effect a contact combustion with combustible materials, means for feeding waste gases of the. combustion process to be controlled to said wire; means for heating said wire to a given temperature b an electric current and means influenced y the changes of length of said Wire effected by the contact combustion, said means being adapted to effect the necessary regulation of the combustion process.

8. In an apparatus for the 'control of combustion processes a wire'containing at its surface a metal adapted to effect a contact combustion with combustible materials,

Umeans for feeding waste 'ases of the combustion process to be contr lled to said wire;

a second wire consisting o, a metal having a similar heat expansion eflicient as the metal of which consists sa "d first mentioned Wire; means for heating both wires to a given temperature by an electric current and means. connected to the ends off said wires 9. In an apparatus for the control of com- I bustion processes a tube traversed by the waste gases, a wire within said tube containing at its surfaces a metal adapted to effect a contact combustion with combustible materials, the one end of said wire being fixed; a second tube, a second wire consisting of a metal having a similar heat expansion coefficient as the metal of which consists said first mentioned wire the one end of which being also fixed, means adapted to effect the necessary regulation of the combustion process correspondin to changes of length of said wire efl'ectedIiy the contact combustion, and springs connecting said last mentioned means to said wires.

10. In an apparatus for the control of combustion processes a wire containing at its surface a metal adapted to effect a contact combustion with combustible materials, means for feeding waste gases of the com bustion process to be controlled to said wire; a second wire consisting, of a metal having a similar heat expansion coefiicient as the metal of which consists said first mentioned wire; means for electrically heating both wires to about 200 Celsius and means connect ed to the ends of said wires facing each 0th r, said means being adapted to effect the necessary regulation of the combustion process corresponding to changes of length of said first mentioned wire effected by the contact combustion.

In testimony whereof I have aflixed my signature.

sumo WinvsoH. 

